docs: def extract_references_from_url(url, headers=None, chunk_size=1024, **kwargs):
      """Extract references from the pdf specified in the url.
  
      The first parameter is the URL of the file.
      It returns a list of parsed references.
  
      It raises FullTextNotAvailableError if the URL gives a 404,
      UnknownDocumentTypeError if it is not a PDF or plain text.
  
      The standard reference format is: {title} {volume} ({year}) {page}.
  
      E.g. you can change that by passing the reference_format:
  
      >>> extract_references_from_url(path, reference_format="{title},{volume},{page}")
  
      If you want to also link each reference to some other resource (like a record),
      you can provide a linker_callback function to be executed for every reference
      element found.
  
      To override KBs for journal names etc., use ``override_kbs_files``:
  
      >>> extract_references_from_url(path, override_kbs_files={'journals': 'my/path/to.kb'})
  
      """
      # Get temporary filepath to download to
      filename, filepath = mkstemp(
          suffix=u"_{0}".format(os.path.basename(url)),
      )
      os.close(filename)
  
      try:
          req = requests.get(
              url=url,
              headers=headers,
              stream=True
          )
          req.raise_for_status()
          with open(filepath, 'wb') as f:
              for chunk in req.iter_content(chunk_size):
                  f.write(chunk)
          references = extract_references_from_file(filepath, **kwargs)
      except requests.exceptions.HTTPError:
          raise FullTextNotAvailableError(u"URL not found: '{0}'".format(url)), None, sys.exc_info()[2]
      finally:
          os.remove(filepath)
      return references